E251 unexpected spaces around keyword / parameter equals
E261 at least two spaces before inline comment
E501 line too long ({96,88,128} > 80 characters)
E305 expected 2 blank lines after class or function definition, found 1
For the remaining spotted issues, I'm not sure whether they should be fixed (or how), or if they maybe should be ignored (I don't treat myself as a Python programmer):
./aggregate6/aggregate6.py:33:1: E722 do not use bare 'except'
./aggregate6/aggregate6.py:44:15: E741 ambiguous variable name 'l'
./aggregate6/aggregate6.py:58:9: F841 local variable 'err' is assigned to but never used
./aggregate6/aggregate6.py:64:1: C901 'aggregate_tree' is too complex (11)
./aggregate6/aggregate6.py:144:1: C901 'main' is too complex (18)
./aggregate6/aggregate6.py:165:13: F841 local variable 'err' is assigned to but never used
./aggregate6/__init__.py:9:1: F401 '.aggregate6.aggregate' imported but unused
For the remaining spotted issues, I'm not sure whether they should be fixed (or how), or if they maybe should be ignored (I don't treat myself as a Python programmer):